dt-bindings: iio: temperature: ltc2983: support more parts

Add support for the following parts:
 * LTC2984
 * LTC2986
 * LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221103130041.2153295-13-demonsingur@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml

@@ -4,19 +4,30 @@
 $id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: Analog Devices LTC2983 Multi-sensor Temperature system
+title: Analog Devices LTC2983, LTC2986, LTM2985 Multi-sensor Temperature system
 
 maintainers:
   - Nuno Sá <nuno.sa@analog.com>
 
 description: |
-  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
+  Analog Devices LTC2983, LTC2984, LTC2986, LTM2985 Multi-Sensor Digital
+  Temperature Measurement Systems
+
   https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/2984fb.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/29861fa.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ltm2985.pdf
 
 properties:
   compatible:
-    enum:
-      - adi,ltc2983
+    oneOf:
+      - enum:
+          - adi,ltc2983
+          - adi,ltc2986
+          - adi,ltm2985
+      - items:
+          - const: adi,ltc2984
+          - const: adi,ltc2983
 
   reg:
     maxItems: 1
@@ -386,6 +397,35 @@ patternProperties:
         description: Whether the sensor is single-ended.
         type: boolean
 
+  "^temp@":
+    type: object
+    description: Active analog temperature sensor.
+
+    properties:
+      adi,sensor-type:
+        description: Sensor type for active analog temperature sensors.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        const: 31
+
+      adi,single-ended:
+        description: Whether the sensor is single-ended.
+        type: boolean
+
+      adi,custom-temp:
+        description:
+          Used for digitizing active analog temperature sensors.
+          See Page 67 of the LTM2985 datasheet.
+        $ref: /schemas/types.yaml#/definitions/uint64-matrix
+        minItems: 3
+        maxItems: 64
+        items:
+          items:
+            - description: Voltage point in nV, signed.
+            - description: Temperature point in uK.
+
+    required:
+      - adi,custom-temp
+
   "^rsense@":
     type: object
     description: Sense resistor sensor.
@@ -413,6 +453,18 @@ required:
 
 additionalProperties: false
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ltc2983
+              - adi,ltc2984
+    then:
+      patternProperties:
+        "^temp@": false
+
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>